Buffy the Vampire Slayer: Fool for Love (2000) [Subway Slayer]: Neck snapped by James Marsters at the end of a fight on a subway train; shown in a flashback sequence as James tells his history to Sarah Michelle Gellar. (Thanks to Disciplesoffufkin)

(Note: As a professional stunt performer, April may have 'died' for other actresses in other films, but I don't know any specific examples.)